1. Field of the Invention
The present invention relates generally to electric circuit apparatus and, more particularly, to motion or shock detecting apparatus in such devices and especially to triggers for novelty items, such as illuminated wearing apparel.
2. Description of the Related Art
In the field of novelty items, especially as they apply to wearing apparel and footwear, it is sometimes desirable to provide an article of manufacture with illumination and/or sound. Especially in the field of footwear, a shoe may incorporate one or more flashing lights for ornamentation, amusement or safety such as when the user is in proximity to automobile and other traffic. A device installed in such a shoe might incorporate one or more light-emitting diodes, a trigger mechanism, circuitry to both recognize trigger signals and to display varying illumination sequences and a battery for energizing the diode(s).
In order to maximize battery life, the diode(s) in the shoe should illuminate only when the user is active, such as when dancing, running, jumping, etc. The diode(s) should not illuminate when the shoe is xe2x80x9cat restxe2x80x9d. A shoe is at rest when it is either not being worn or is worn but the user""s feet are inactive (such as when the user is sitting down). Accordingly, such a shoe might incorporate a trigger mechanism and switch to connect the diodes to the battery when pressure is applied or when the shoe is set in motion through impact, acceleration or otherwise.
Prior art in this area has developed along two lines: 1) the development of a trigger and circuit switching mechanism and 2) the development of increasingly complicated light displays and illumination patterns. A motivating factor in motion sensor development for apparel, toys and other such items, has been the constant pressure to reduce the costs and complexity of the sensor and switch mechanism. Most such devices include a method of biasing part of a circuit in a position that creates either an open or a closed circuit. Movement causes that piece of the circuit to move away from its biased position, thus closing or opening the circuit based upon the prior position of the device. The change in state from open to closed, or closed to open, triggered the targeted event.
The state of earlier prior art technology is demonstrated in U.S. Pat. No. 6,087,951 (the ""951 patent), to Ramsden. That technology uses a fixed magnet, a moveable magnet and an activator switch. The moveable magnet is biased such that it rests in contact with the fixed magnet. A pre-defined amount of force caused by movement, is sufficient to caused the moveable magnet to move away from the fixed magnet, sliding towards an activator switch. The moveable magnet pushes the activator switch with sufficient force to trigger the switch.
Some of the disadvantages of that type of design are described in U.S. Pat. No. 5,965,855 (the ""855 patent), by Tanazawa. According to the ""855 patent, the moveable magnet design requires a relatively large amount of force to activate the sensor switch and correspondingly larger equipment to sense the activation of the switch. The ""855 patent incorporates a metal ball enclosed in a chamber and surrounded by four parallel electrode pins. The ball is biased by a magnet. Movement breaks the contact between the ball and the magnet and allows the ball to contact two of the electrode pins. Contact between the metal ball and the electrode pins completes a circuit and triggers a change of state signal. The pins are positioned such that contact between any two pins defines upward, downward, right and left movements.
The second area of development regards the nature of the light displays. Technology in this area started with the display of a single light and later advanced to display a row of lights, blinking in a defined sequence. This prior art further developed to the point of pseudo-animation by having different scenes portrayed on a film attached to the shoe. A series of lights flash behind the scenes to cause the entirety of the graphical presentation on the shoe to appear animated.
Such a shoe incorporates several lights and an automatic circuit for flashing the lights in a desired sequence. One example of such a shoe is found in U.S. Pat. No. 5,457,900. This shoe can flash a fixed message, such as xe2x80x9chixe2x80x9d. Another example is found in U.S. Pat. No. 6,112,437 (the ""437 patent), issued to Lovitt, for An Article With Animated Display. This shoe displays light in a sequence that illuminates sequential panels of a film, to show a person running.
The combined goal of the two areas of development has been to make a switch device that is smaller, cheaper, has a longer battery life and produces an interesting and novel visual display. The present invention addresses each of these development goals.
It is an object of the present invention to provide a motion sensitive switch that can be used in apparel, small devices and toys and that is cheaper and better than currently existing motion sensitive switches. It is a related object to provide circuitry to accompany the switch that allows for multiple patterns of random and ordered output.
In accordance with these objects and with others which will be described and which will become apparent, an exemplary embodiment of a motion sensitive switch in accordance with the present invention comprises a housing unit that contains, among its basic elements, a motion sensitive switch mechanism, a battery and electrical circuitry.
The switch mechanism is contained within a smaller housing unit and comprises a magnet, two electrically conductive contact strips/pins (one being positively charged and the other being negatively charged) and an electrically conductive ball. The pins or contact strips are positioned between the magnet and the ball. The magnetic attraction biases the ball towards the magnet and into contact with the pins. Because the ball is electrically conductive, it completes a circuit between the two pins. Thus, in the biased position, the circuit is closed.
On motion, the contact between the pins and the ball is temporarily broken and the ball moves away from the electrically conductive pins. The circuit is broken and a change of state signal is sent to the electrical circuitry. When the ball again makes contact with the contact strips, a second change of state signal is sent. Upon receipt of the second change of state, the electrical circuitry activates the output device. The output device could be based upon illumination, audio output, any other form of electrically stimulated output or a combination of these. When the switch comes to rest, the ball again moves to its biased position, creating a closed circuit that positions the switch to detect a new change of state sequence.
In another exemplary embodiment of a motion sensitive switch in accordance with the present invention, the sensor switch does not include a magnet. In this embodiment, the electrically conductive ball is magnetized and the pins are comprised of a Ferro-magnetic, electrically conductive material. The ball is therefore attracted to the pins. In its biased position, the ball is at rest against the pins. On motion, the magnetic attraction and the circuit are temporarily broken. On returning to the biased position, the circuit is re-established and the change of state triggers the output device.
It is an advantage of the present invention that the motion sensitive switch contains fewer components than prior art. It is therefore less expensive and provides less opportunity for functional failure. This invention therefore provides a means by which a motion sensor switch can be more economically placed in wearing apparel, shoes and small devices.